Cinematographic projection apparatus



May 12, 1931. ENGELMANN 1,804,499

CINEMATOG RAPHIC PROJECTION APPARATUS Filed Oct. 4. 1927 Fig.4

'Jnuznior Patented May l2, i931 UNITED STATES MAX ENGEIMANN, F LA'USA, GER-MANY GINE'MA TOGRAPHIC PROJECTION APPARATUS Application filed October 4, 1927, Serial No.

The present invention relates to acinematographic projection apparatus and especially to apparatus for cooling the film or the film track.

In the projection apparatus in which the picture band or film is illuminated by a very strong source of light, the band or film is so strongly heated that it would be ignited if the light were permitted to fall upon the film at rest. However, even when the apparatus is in operationthe film becomes heated and in time becomes brittle. In addition to the film, the film track and the neighboring parts of the apparatus become strongly heated. I

In order to avoid these disadvantages air blasts have already been ,,proposed which blow a stream of air under pressure against the film and the film track, and thus an ex- -cessive heating is prevented. In these proposed apparatuses the air from the compressor was led through tubes of fiexible material from the exterior of the apparatus to the nozzles through which the air under pressure was blown against the places to be cooled. These nozzles are positioned ve:y near the film track or the film window, and it is known that these flexible air tubes which lead to the nozzles are very troublesome since they prevent the operator from operating the film door easily and quickly. If rubber tubing is used for conducting the air under pressure, there also arises the great danger of easily damaging it in case it comes too near the lamp house or other part of the apparatus. 7

According to the present invention a rigid tube is employed and it is placed in the interior of the completely inclosed' mechanism.

The conductor carrying the air under pressure enters the casing at a suitable place, while the tube proceeds "to other places arid leads into the blast nozzles. The tube may 4 branch ofi at difierent points in order to 223,977, and in Germany October 29, 1926.

supply several nozzles at the same time with air.

Figure 1 shows the apparatus with the lamp house and air compressor. Figure 2 shows the casing containing the driving mechanism with the back or outside wall removed. Figure 3 shows the said casingfrom the side and having the exterior wall partly broken away to exhibit the parts. Figpre 4.- is a view looking from the left side of igure 3 showing the position of the film in reference to the nozzles. c

The compressed air is produced by the compressor 1 and is conducted to the a paratus by means of a tube conductor 2. T e base 4 go of the housing is provided with an opening and carries a connecting sleeve 5. Connected with the sleeve 5 and within the casing is the tube 6 which leads from the sleeve 5 to a distributor 7 from which lead two more tubes 8 and 9. These pass through the side wall 10 of the casing and end in nozzles 11 and 12, which are positioned near the-film I track 13 or near the film window 14.

The tubes 6, 8, 9, the distributor 7 and the nozzles 11 and 12 are made of rigid material as described above and may be ofmetal such as brass or nickel or of a non-metallic and fireproof character such as asbestos in combination with a suitable binding a nt, such asbestos compositions being well own in the art. The tube 2 leading from the compressor may be of strong rubber hose but is also preferably of metal.

Having described my invention what I .80 claim is:

The combination with a cinematographic projection head and a film gate supported by said head and disposed outwardly thereof of a vertically extending pipe arranged wit said head, 'a coupling arranged upon the upper end ,of said pipe, branch pipes each havingoneendconnectedtp said cou ling and its opposite end extended exteriorly of the head and projecting near the film gate on the latter, 'a. nozzle secured and connected to each of said projecting ends of the branch pipes extended exterior? of the head, said nozzles being disposed a jacent the film gate on each side thereof, and a. main coupling arranged exteriorly of the head and connected to the lower end of the vertically extending pipe within the head, whereby an air supply conduit may be directly connected to said coupling for the purpose specified.

In witness whereof I have hereunto set my hand.

MAX ENGELMANN. 

